Shut-off devices for infusion devices or blood-drawing devices are already known that can be connected by flexible tubes or injection syringes to an emplaced catheter in order to supply an infusion fluid to a patient or in order to remove blood or other body fluids from the patient.
In order to shut-off fluid flow of such a connection both after completion of the catheterizing process and also in the case of an emplaced catheter, a cannula closure piece with a sleeve-like casing of the type described above has been utilized. In such devices a pressure body is constructed as a pair of balls, each of which is arranged along a diametrically opposite lateral side of the flow passage and its associated elastic tube piece. A U-shaped pusher grips both balls and in one of its end positions permits the tube piece to leave the passage free and open, while in the other end position of the pusher, the balls are moved toward one another to close the passage.
This known cannula connection, however, is not only complicated in construction, but, above all, the movement direction or stroke of the pusher or actuator extends lengthwise in the direction of the cannula, whereby the operator must use two hands in order to use the device. Furthermore, the movement of the pusher or actuator in the direction of the operating cannula frequently causes (blood) vessel injuries; and as can be vividly imagined, catheterizing with such an instrument can be extremely painful.
Accordingly, there is a need in the art for the provision of a shut-off valve or device of the type mentioned that is not only simple to produce and easy to operate, but is capable of being operated without resulting in injury or severe pain to the patient.